Fluid-structure interaction

These studies are used to assess the risk of fatigue failure in pipelines subjected to acoustic excitation. Acoustic excitation is generated at valves and pressure reduction devices, and propagates downstream in the piping. These phenomena can coincide with pipe ovalization modes and generate significant stresses at line discontinuities.

Selon les conditions de fonctionnement, l’écoulement du fluide dans les tuyauteries peut générer des turbulences, qui peuvent induire des niveaux vibratoires non-négligeables et endommager la tuyauterie et ses composants rattachés de façon prématurée. Il est donc nécessaire de repérer les lignes critiques parmi toutes les lignes de l’installation.

Acoustic resonances can be excited in “dead branches” of pipes by fluid flow (FIP). Flow around singularities causes vortices to form at specific frequencies. In the case of sensors inserted in the flow (e.g. temperature probes), the vortex frequency does not have to match the probe’s natural frequency (VIV). Methods can be employed to minimize the risk of fatigue breakage for both types of phenomenon.

Some components generate pulsations that can propagate through the pipe network. These pulsations can be amplified by acoustic and/or mechanical resonances in the piping system, placing excessive stress on the structure. Vibratec carries out finite element and pulsation studies (in accordance with API 618 and API 674) to predict and optimize these vibration levels.